Set endpoint with db_host-option in boss.config
Add all models within the running CB instance to DynamoDB
Add global/local config values for read/write capacity. 

Global values is stored in boss.config:
{db_read_capacity, X}, %% X is an integer
{db_write_capacity, Y}, %% Y is an integer


Local values is stored within the model as a function that returns a proplist:

dynamodb_settings() ->
    [
     {range_key, X}, %% X is an atom and should address one of the field within the current model
     {db_write_capacity, Y}, %% Y is an integer
     {db_read_capacity, Z} %% Z is an integer
    ].
Use application:which_applications/0 instead of application:info/0
Capacity is now read from configuration. Two new attributes: 'range_key' and 'primary_key'. 

Users can define a global capacity configuration:
{db_read_capacity, X :: integer()},
{db_write_capacity, Y :: integer()}

It's also possible to set the capacity of specific models:
{db_model_read_capacity, [{ModelName :: atom(), X :: integer()}]}
{db_model_write_capacity, [{ModelName :: atom(), Y :: integer()}]}
Merge pull request #110 from burbas/dynamo_db

Updates on the DynamoDB adapter
Fixes an issue where if primary_key-attribute was used on a field other than "id" the dynamodb-adapter would get into a infinite loop and eventually crash.